Rule protractor



. Peb. 3, 1925.. 1,524,730 4 M. c. cAlN RULE PROTRACTOR Filed DeC. 23, 1921 NIMH MILE.

atto: myn

Patented Feb. 3, 1925. Y

MARSHALL CORNELIUS GAIN, OF CLARKSDALE, ARIZONA.

RULE PROTRACTOR.

Application filed December 23, 1921. Serial No. 524,471.

To all whom t may concern.'

Be it known that I, MARSHALL C. CAIN, a citizen of the United States, residing at Clarksdale, in the county of Yavapai and State of Arizona, have invented certain new and useful Improvements in Rule Protractors, of which the following is a specification.

This invention relates to improvements in protractors adapted for use in connection with folding rules.

The primary object of the invention is the provision of a. protractor device of novel formation adapted for use in connection with the ordinary folding measure rule, and which may be mounted concentric with a pivotal point of connection of cooperating rule measuring members and for determining the accurate angular relation of said rule measuring members.

A further object of the invention is the provision of a protractor arrangement of the above described character, which is simple in construction, durable, easy to manufacture, and which may be assembled to a pair of pivotally connected cooperating rule measuring members in a facile manner for determining the angular relation of said rule measuring members.

In the drawing, wherein similar reference characters designate corresponding parts throughout the .several views Figure 1 is a perspective view of a pair of pivotally connected measuring parts of an ordinary foldable rule, showing the improved protractor member mounted thereon for determining angular relation of said ru/le parts.

Figure 2 is a perspective view showing the means by which the preferred type of protractor device is attached to a measuring rule.

yFigure 3 is a perspective view showing the modified means by which the improved protrae-tor may be mounted upon a foldable rule.

Figure 4 is a bottom plan View of the preferred type of protractor illustrated in Figure 2 and showing the same mounted upon the measuring parts of a foldable rule and adjacent a joint of said foldable rule.

Figure 5 is a bottom plan view showing the manner in which the modified form of protracting device illustrated in Figure 3 is assembled to a measuring rule.

Figure 6 is a cross sectional View taken on the line 6 6 of Figure 4. y

Figure 7 is a cross sectionall View taken on the line 7-7 of Figure 5.

In the drawing, wherein for the purpose of illustrationy is shown the preferred embodiment of myl invention, the letter A designates an ordinary foldable measuring rule including the various measuring rule members or parts B which are. Pivotally connected to be held in extensible relation to provide a relatively long rule, or which may be folded one upon the other to provide a foldable device, which occupies a relativef ly small space. The measuring members B of the rule A are pivotally connected at a point 10 by the ordinary spring fastener mechanism. The pivot point 10 is disposed adjacent the ends of a pair of the measuring rule members B, and in such mannerthat a short portion 11 of each of the members B project for a short distance outwardly of said pivot po-int 10, and' which projecting ends 11 cooperate with various parts of the j improved protractor device C to be subsequently described. The indicia 12 are of course provided upon the surfaces ofthe i parts B of the rule A in the ordinary manv ner.

The protractor arrangement C includes an annular or ring shaped member 15 having a central opening 16 therein. The upper face I17 of the protractor member C is graduated as at 18 circumferentially upon said face, said graduations, of course, radiating from the center of the annular member C and preferably indicate degrees, al-

though any system of angular measurement may be inscribed or provided upon the upper surface 17,. The bottom surface 20 of the member 15 is provided with attaching means for Vmounting said annular member 15 upon a rule measuring member B;

In the mounting of the protractor device C upon the rule A, it is preferred that the ring shaped disc 15 be disposed coucentric with the pivot 10 of a pair of pivotally connected members B and intermediate said members. To this end, the bottom 20 of the member 15 is provided with a substantially U-shaped bracket 22, which has the outer flanges or legs 23 thereof soldered or otherwise securely attached upon the bottom surface 2O and adjacent a marginal edge of the annular member 15 in order to provide a flap `or opening 2li as formed by the' connection ofthe meinber 22 in its position upon the bottom 20. The bottom 2O' is provided diametrically Vopposite the bracket 22 with a pair of resilient arms 25, which are solderedtheretol by attaching legs 26 extending outwardly therefrom, and in suchV manner that the spacing of therinside surfaces 28 ofthe resilient arms 25 is relatively the same as thelength of the slot 24 providedrby bracket 22. It is preferred that the varms 25 project outwardly fromv the marginal edge of the protractor member 15 as is clearly illustrated in Figure 2 of the dran# ings. f y i 11n the mounting of the` improved protractor arrangement C'upon the rule A, the members `B of the rule are slipped through the opening 16 provided by the annular inembeil, vuntil the proper joint ,or point of pivotal connection-of the rule A is reached upon which it is desired to mount the Vdevice C. The irst step lin mounting the protractor device C is that of arranging the protractor device as to yslip the projecting end 11 of the lowermcst rule memberl B into the opening or slot 2t provided by thebracket 22 of the annular disc 15. 1n this position, the upper face 17 containing the angular graduations 18 faces the lower surface of the upper rule member B. The spring arms 25 are so positioned as to engage the lateral edges 3() of the lower Lrule measuring member B. Inthis manner, the device C isrigidly and detachably mounted upon the lower member B of a rule A, and is so adjusted lin vposition thereon that the center of the yopening 16 of the annular disc `15 is concentric with the pivot point 1() which connects the' members B of' a rule A. As can readily be seen from Figure 1 of the drawings, the outer'zprojecting end 11- of vthe uppermost rule member B `is provided with an arrow or other: indicating mark 3l, which assumesr a determined position with respect to the angular indicia 18 upon relative movement ofthe rule members B, Vand whereby the exact angular relation of said members B,` may be determined.

A modified forni of attaching means for the disc 15 is illustrated in Figure 23; This modified form comprehends the provision of a segmental attaching l. member 35 for mounting upon the bottom surface 20 of theJ protractorv ring 15.V The segmental 'attaching member 35, however, is so shaped, as to provide the upwardly projecting U-shaped portion 36 upon one edge of the ring member 15, and which provides the' slot or opening 37 exactly similar to the" slotl 24 above described. Upwardly projecting iianges 38 upon the ends of the attaching member 35 are so formed that their inner surfaces 39 align with the inner surfaces of the ends -ofthe slot?, and which arms 38 are positioned diametrically lopposi'tely-Y on .the ring-member 15 from that of the U-shaped bracket 86. The niember 35-fmay be soldered or otherwise securely attached to the bottom surface 20. The attachment of this modified forni ot protractor upon the rule A. is altogether similar to that above described.

The relatively large circularopening 10 as provided by the improved protractor device C, of course, permits the connecting and" wearing mechanismv of the rule fr at a point of connection of two of thel members lB to be disposed therein, in such manner as to not interfere in any manner with the'eHicieney 'of the rule A, or of operation of the pivotally connect-ed membersv B in connection with the protractor devicev C. As cani be seen from Figure 1, the ringdisc or member is assembled intermediate 'the top surface and bottom surfaceof the bottom 'and top members B respectively, and with the extreme outer end of Ithe upper member B which contains the indicating mark 51 overlying for a short distance the upper surfac'e14 of the ring 15. rlhus, the protractor device Gis securely mounted upon one' of the rule `Vmembers l in rigidmanner to provide pivotal action of the other' member B thereupon, and

`without liability of accidental detachment or shifting ofthe protractor arrangement. From the foregoing, it is obvious that' the `ruleA Acan be used for various purposes other than mere linear measurements,- since by the addition of the protractorfdevice C angular measurements can be vaccurately determinedf This 'device' will lbe found of great utility in construction work', plumbing work and other trades in which it is desirable 'to determinev angular measurements with a considerable degree of accuiacy. i g A Various'changes inthe'shape, size and arrangement of parts may be` made to the ,forms of the invention. herein 'shown 'and described without departing from the spirit "of the invention or the scope of the appended claims.

1. device of the class `described comprising a substantially ring -shaped 'member havingI indicia on one side thereof andk provide'd upon its .opposite sideA with an attaching bracket adjacent a marginal edge of said ring shapedV membertoprovide a receiving opening, and resilient Vattaching arms on said last mentioned-'side of said ring shaped member for cooperation with said receiving opening to detachably mount the protractor device upon alsu'pport.

2. A device ot' thecla'ss described-com` prising a protractor member having indicia on one side thereof, and provided With means mounted upon its opposite side for attaching said protractor member to a sup port, said means including an attaching opening adjacent one edge of said protraetor member and diametrically opposed attaching arms in alignment with the receiving opening.

3. The combination With a foldable measuring rule having the measuring rule members thereof pivotally connected to provide ends one on each member projecting from the pivot point, of an annular shaped protractor member, and means on the bottom of said protractor member for engaging one measuring rule member adjacent its pivot connection with a second rule measuring member to securely mount said protractor member intermediate said rule measuring members, and concentric with the pivot point of said rule measuring members, whereby said second mentioned rule measuring member may be swung on its pivot to indicate various angular positions on said preti-actor With respect to the rule measuring member on Which said protractor is mounted.

4. In a device of the class described, the combination With a pair of pivotally mounted parts of a collapsible linear measure, the ends of said parts projecting outwardly from the pivot point thereof, of a protractor member of annular shape, said annular' shaped member having indicia on one surface thereof, and provided upon its opposite surface With an attaching member providing an opening for slipping over the end of one rule measuring part to concentrically position the annular member With respect to the pivot point of the connected rule measuring members, said attaching member including resilient attaching arms opposed to its opening, and adapted to engage the lateral side edges of the ruleV measuring member upon Which it is mounted, said protractor device When in such position having the annular member disposed intermediate the rule measuring members and Whereby the extending end of one of said rule measuring members over lies the indicia of the annular member to assume various positions thereon indicating annular relative positioning of the pivotally connected rule measuring members.

5. A measuring device comprising a pair of pivot-ally connected sections of a linear measure, a protractor member having a surface thereof delineated to designate degrees, means for attaching theprotra-ctor member betvveen said sections of the linear measure with the degree delineations concentric With the pivotal connection of the sections, the other of said sections having an indicator mark thereon for cooperation with the degree delineations of the protractor member.

MARSHALL CORNELIUS GAIN; 

